If log y = tan–1 X, show that : (1+x2)y2+(2x–1) y1=0.
Note: y2 represents second order derivative i.e. and y1 = dy/dx
Given,
log y = tan–1 X
∴ y = ……equation 1
to prove : (1+x2)y2+(2x–1)y1=0
We notice a second order derivative in the expression to be proved so first take the step to find the second order derivative.
Let’s find
As
So, lets first find dy/dx
Using chain rule, we will differentiate the above expression
Let t = tan–1 x => [
]
And y = et
…….equation 2
Again differentiating with respect to x applying product rule:
Using chain rule we will differentiate the above expression-
[using &
]
Using equation 2 :
∴ (1+x2)y2+(2x–1)y1=0 ……proved